1. Field of the Invention
The present invention relates to a large-sized display apparatus arranging planar display devices, and more particularly to a large-sized display apparatus for use outdoors.
2. Description of the Related Art
Heretofore, with respect to this type of large-sized display apparatus, originally, a method which arranges monochroic CRTs (cathode ray tubes) as display devices has been put into practice. Thereafter, a display device which includes a plurality of pixels in the inside of the display device by applying a principle of a CRT or a discharge tube has been developed and the resolution has been remarkably improved. Thereafter, a method which arranges liquid crystal display devices as described in following patent documents 1, 2 has been put into practice. Then, a method which arranges plasma display panels or vacuum fluorescent display has been proposed on a trial basis. In this manner, various types of display devices can be used for constituting the large-sized display apparatus. Recently, the method which comprises the large-sized display apparatus arranging LEDs (light emitting diodes) has become a mainstream. In this manner, the large-sized display apparatus is now applicable to various applications such as in-door high-resolution application, outdoor ultra-high-luminance application, light-weighted and thin building-wall-surface application.
[Patent document 1] JP-A-2002-72928
[Patent document 2] JP-A-2004-341468
This type of conventional large-sized display apparatus, when used outdoors in a state that a plurality of planar display devices are arranged, as in the case of display modules including display devices, is configured such that a sufficient waterproof measure is applied to electronic equipment inside a frame which supports the apparatus as a whole thus enabling the installation of the large-sized display apparatus in an arbitrary environment. Here, there may be a case in which a front glass for protecting a plurality of display modules as a whole from rainfalls is arranged in front of the apparatus. In such a case, the frame itself has to possess a sufficient strength and reliability. Accordingly, there has been a drawback that a manufacturing cost of the large-sized display apparatus becomes large as a whole and weight of the large-sized display apparatus increases corresponding to a size of the front glass.